I pay the no contract $30 per month for Verizon on my iPad. I can stop and start it on a monthly basis anytime. I'm not sure what is simpler. Only once did I exceed the 2 gigabytes in a month on our travels and being on the road I just paid another $20 to continue on. Whatever the extra was I never ran out. I have unlimited AT&T on my iPhone so I can be pretty much always connected.
Lately, at least in the areas I've traveled which tend to be more remote like Voyaguers National Park as one example. AT&T has outperformed Verizon in the boonies. That didn't use to be the case. The AT&T 4G is very fast. The Verizon LTE is oversold, IMO and their 3G is slow compared to AT&T.
Just looking at coverage maps, the way we travel I would not consider anything but Verizon and AT&T. I had a Virgin Mifi card that used Sprint and found it almost useless outside metro areas or major freeways despite their lying coverage maps.
